Claw operated film-feed sprocket drive



April 7, 1953 T. G. FREDERICK CLAW OPERATED FILM-FEED SPROCKET DRIVE 2 SHEETS--SHEET l Filed April 29, 1947 INVENTOR TILGHMAN G. FREDERICK www@ ATTO R N EY April 7 1953 T. G. FREDERICK 2,633,773

CLAW OPERATED FILM-FEED SPROCKET DRIVE INVENTOR TILGHMAN G. FREDERICK ATTORNEY Patented Apr. 7, 1953 CLAW OPERATED FILM-FEED SPROCKET DRIVE Tilghman G. Frederick, New York, N. Y.

Application April 29, 1947, Serial No. 744,600

9 Claims.

This invention relates to mechanisms for feeding motion picture film and more particularly to intermittent driven sprockets for picture lm feeding mechanism and to improved means for driving the sprocket. The invention relates to these and other improvements for continuous automatic projectors though it is noted that in the claims the invention is not limited to continuous projectors or to projectors.

One object of the invention is .to provide an improved mechanism of this kind which will allow the sprocket and i'ilmto remain a long time stationary in lm projecting and exposing position and will then operate the sprocket to feed the lm quickly to the next projecting or exposing position and then stop the sprocket and film with an easy smooth movement which will not cause vibration or injure the lm.

Other objects of the invention are to provide an Y improved ciling system fora film feeding mechanism and to provide a film feeding device of this kind which is substantially noiseless in operation and free from lost motion or vibration, and which will run a very long time without wearing out the film.

Additional objects of theinvention are to effect simplicity and efficiency in such apparatus and to provide an extremely simple apparatus of this kind which is very economical, durable and reliable in operation, and economical to manufacture and easy to install.

Still other objects of the invention will appear as the description proceeds; and while herein details of the invention are described in the specification and some of the claims, the invention as described insome of the broader claims is not limited to these, and many and various changes may be made without departing from the scope of the invention as claimed in the broader claims.

The inventive features for the accomplishment of these and other objects are shown herein in connection with an improved reciprocatory-claw operated sprocket film feed mechanism which briefly stated, includes a lm feed mechanism it stationary at each limit of movement.

`A sprocket shaft mounted in said side walls below said drive fshaft Acarries an exterior. master sprocket, 'and carries a toothed wheel Within the (Cl. 88-18.Z)

housing. .A lever pivotally mounted on said reciprocatory member has a lower claw engageable between the teeth of the toothed wheel, the upper end of the lever being urged against a cam face of an in-and-out cam on said main shaft, lsaid in-and-out cam face being contoured to hold the claw between and away from said teeth when the member moves in respectively opposite directions.

A friction block having a bearing bore snugly frictionally received on the sprocket shaft and having a radial split extending to the bore, is provided with means to hold the disk from rotating and with means for adjustably yieldably pressing the walls of the split toward each other to adjustthe friction on the sprocket shaft to prevent' undesired vibration.

A worm fast on the rear of the main shaft within thev housing, engages a worm thread on a countershaft rotatable in the rear corners of the side walls and projecting near the master sprocket and carrying a supply and take-up sprocket on the projecting part of the countershaft for conductinglm to and from a lm gate and the master sprocket. j

A grooved pulley fast on the main shaft and a grooved idler rotatably mounted at the bottom of the housing carries a belt disposed over said pulley and idler for carrying oil filling the lower part of the housingof the main shaft where it spreads to Various parts to lubricate them.

In the accompanying drawing showing, by way of example, one of many possible embodiments of the invention,

Fig. 1 is a side elevation of the mechanism; partly in vertical section through the abutments, a side Wall ofthe housing being removed;

Fig. 2 is a transverse sectional view taken on the line 2-2 of Fig. l;

Fig. 3 is a horizontal sectional view taken on the line 3 3 of Fig. 1;

Fig. 4 shows an enlarged diagrammatic view of the cams; and

Figs. 5 and 6 are fragmental side elevations, partly in section, showing respectively upper and lower stationary positions of the claw.

The various parts of my improved film feeding mechanism are carried in and by a narrow housing I0 having front, rear, bottom and side walls Il, I2, I3, I4, I5, the front and rear walls Il, I2 being provided with alined main forward and rear bearings I5, I1 carrying a main drive shaft I8 projecting at both ends and adapted at either end to be connected to, and rotated by, a suitable source of power.

Opposed vertical guide strips I9 held by screws 2d on the forward wall Il have inner undercut' grooves 2l (Fig. 3) on opposite sides of the shafty said grooves receiving a reciprocatory plate member 22 slidable in said grooves and provided with a large central opening 23 receiving said main shaft, the plate being provided at its lower edge with spaced bearing ears 24 having alined bearing bores transverse to the path of the plate.

A feed cam E mounted fast on said main shaft adjacent to said opening has a peripheral cam face including a long outer land portion 21 of about '72 degrees and large radius, a short opposite land portion 28 of smallv radius and a pair of outwardly curved intermediate portions 2s, sii merging into said land portions 21, 28. take-up cam 36 mounted on said main shaft ad:- jacent to and secured fast to the feed cam 2d has a peripheral cam face including a long outer land portion 31 of about 96 degrees and large constant radius as great as the radius of the outer land portion of the feed cam, a short opposite land portion 38 of small constant radius and a pair of outwardly curved intermediate portions 38, lill merging into the land portions of radii respectively slightly longer than the correspondn ing radii of the feed cam, said portions 31, 38, 39, fifi of the take-up cam being respectively adjacent to the corresponding cam portions 31, 29, 3i? of the feedrcam. Said cams ZE, 35 are provided with a pair of. small alined openings eccentric to the main shaft receiving coupling screws 42 for holding the cams against rotation relative to each other.

An upper abutment plate 4E integral with the reciprocatory plate 22 and provided from material bent from said large opening 23 is disposed above the cams and forms a horizontal upper abutment engageable with the take-up cam A lower abutment plate 48 integral with the reciprocatory plate 22 below the feed cam forms a horizontal lower abutment engageable with the feed cam and terminating short, of the taireup cam 36. The cam portions 21, 28, 29, 3U, 31, 38, 3Q, 453 are of such radius and said abutments 46, t8 are of such distance apart that when the long land portion 31 of the take-up cam engages the upper abutment 4B, the opposite land and intermediate portions 28, 29, 3G of the feed cam will one at a time engage the lower abutment, and when the long land portion 21 of the feed cam engages the lower abtutment, the short land and intermediate portions 38, 39, 4i) of the take-up cam Will one at a time engage the upper abutment 45.

A cam collar 50 having a hub fast on the main shaft has a cam 5Iv transverse to the shaft provided with an in-and-out cam face faced toward Y and spaced from said cams and comprising high and lowland portions 52, 54 and inclined intermediate portions 53, 55 connecting the land portions. An oscillatory shaft 56 in said transverse bores of the ears 24 carries fast thereon between said ears a lever 51 of metal plate having between its edge at said shaft a large cut-out 58. rhe upper part of the lever is rearwardly extended and has, between the cam collar 50 and the take-up cam 36, an upwardly extended end 5S carrying a ball-cup Bil adjacent to the periphery of the inand-out cam and receiving a bearing ball ti engaging the cam face of the in-andout cam. The lower arm portion `51 of the lever 51 extends downwardly and has a rearwardly turned claw `t2. A helical spring 163 carried on said oscillatory shaft at said large open- A fiber l ing of the lever and anchored at 64 to the plate 2.2 and at 55 to the lever serves to press said ball against the in-and-out came face. The portions 52, 53, 5t, 55 of the in-and-out cam face are deto allow the spring E3 to hold the claw t2 rearwardly when the reciprocatory plate 22 moves downwardly and to hold the claw forwardly when the reciprocatory plate moves upwardly.

Alined bearings 69 near the lower forward corner of the side walls carry a master sprocket shaft 1t projecting at one end and carrying master feed sprocket 1|, such shaft carrying fast thereon within the housing a laminated toothed wheel 12 made of hard fiber provided withlarge widely spaced teeth 13 substantially sprocket-tooth distance apart, each tooth 13 comprising a somewhat cylindrical outer portion 1d axially parallel to the sprocket shaft and a slightly narrower inner neck 15. Said claw t2 is made thiol; from. top to bottom and has a rounded inner end'l', a curved upper face il, and a lower face 1,8 curved approximately co axially with the oscillatory shaft 56. IThe portions of said cams 26, 35, 5i, the lengths of the lever arms 51', 5S and the faces 11, 1S of the claw are so related that the claw is in retracted position as it moves upwardly, and then while ie reciprocatory plate is stationary, the claw moves inwardly, out of, Contact with the tooth next above the claw to cause the face 1B to slide evenly on the upper'face of the cylindrical portion 14 of a tooth next below, just above the level of the axis of the sprocket shaft 1G. Then the claw moves downwardand engages the cylin drical portions 1A of both adjacent teeth, as in Fig. G, before the claw reaches its lower limit of movement, and is retracted while the reciprocatory plate 22 is stationary in its lowest position, thus top revent` overfeed of the toothed wheel. The curved claw faces 11, 18 avoid movement of the toothed wheelVV during insertion and retraction of the claw.

A friction device 8G comprises cooperating members El of compressed fiber together constituting a disk-shaped` body having large half bores 32 providing a large bearing bore snugly received on a drum -82' (Fig. 2) fast on the master sprocket shaft 1U between the toothed wheel and the side wall, the block halves Vhaving pairs of spaced ears 83, 86, there being a space of appreciable width between the bloeit halves extending to the drum 32'. A screw 85 passing through an ear -84 into the adjacent side wall, and a collar 8K6 (Fig. 3) on the screw between such ear and said, side wall cooperate to hold the dish from rotating and to hold the device Bc spaced from the side wall. EachV pair of said ears is provided with alined bores, the upper borebeing larger in diameter than the lower bore, said bores receiving a headed adjusting screw t5 passing loosely through the upper bore and hat ing threaded connection in the lower bore. A helical spring 81 compressed between the screw head and the upper ear, serves for adjustably yieldably pressing the ears towards each other to adjust the friction of the block half at the bore 82 upon the drum l82 to hold the shaft stationary without vibration while the claw is disengaged from the toothed wheel 12.

Alined bearings 89 near the upper rear corners of the side Walls carry a countershaft 30 projecting near and spaced from the4 master sprocket 1I. Said shaft 90 carries fast thereon Within the housing ra Worm wheel 9| meshing with a worm 92 mounted fast on the rear of the main shaft.v A take-up sprocket 95 fast on the countershaft in the plane lof the master sprocket, is adapted to receive film 95 from the master sprocket and deliver it to a take-up reel (not shown). A supply sprocket 9'I loose on the countershaft, and off-set from said plane is yieldably held' against rotation, relative to the shaft 90, by a helical spring 98 receivedV on the countershaft 90 and having its end anchored 'to the sprockets 95, 91, to allow yielding movement of the supply sprocket l to'yieldably'draw fllm from a supply reel and deliver'it to a film gate 99 and thence to the master sprocket l0. f

Ar grooved pulley |00 fast on the main shaft between the worm 92 and in-and-out cam, and a grooved idler |0| rotatably mounted on a bracket |02 mounted on the bottom wall I3 carry a belt I 03 of helical spring wire disposed over said pulley and idler. A trough |05 (Figs. 2 and 3)v mounted on the wall I4 has a closed upper end |06 and almost touches the belt |03 and inclines downwardly to and forwardly to a position near the lower part of the cam 36.

The lower part of the housing is filled with lubricating oil |04 up to a level to cover said idler pulley and the sprocket shaft 'I0 and-part of the toothed wheel TZ. When the mechanism is operated, the claw and tooth wheel are lubricated, and oil is carried by capillary attraction of the belt |03 to the grooved pulley |00, whence it spreads to the worm 92, the worm WheeLthe trough |05, the cams 2B, 36, 5|, said ball 6I and the various bearings. A deflector plate v|00 having a margin secured to the lower face of the lower abutment plate and extending to near said guides I9, and upwardly bent underY and projecting beyond the take-up cam 36, and under the end of the trough I05 rserves to deflect oil from the trough to the cams 26, 36, the guides I9 and thence to the grooves 2| and the side edges ,of the reciprocating plate 22.

The opening of the shutter, (not shown) is of such size as to remain openthrough about 90 degrees of the rotation of the shaft Il, and has a position -to open just after the plate member 22 has reached its uppermost position of Fig. l and to close a few degrees before the plate member 22 starts its downward travel. As the radius of the cam por-tion 31 is constant, the plate member 22k and the film are not moved while the shutter is open. The cams rotate in the direction of the arrows of Fig. 4. fi n 'After the plate member reaches its uppermost position and before it begins to descend an inclined cam face 53 (Figs. l and 4) and the raised land cam face 52 of the in-and-out cam reach theball BI of the follower lever thereby-causing the claws 62 to enter between teeth 'I3 as in Fig. 5. I

The'cam portions 30, 2S, 39, 21 are so designed that the plate 22 and film remain'` stationary in the upper position when the claw E2 moves into l.the interdental spaces of the wheel 12; and the wheel 12the film and the plate 22 start slowly and the plate moves down from the position of Fig. l to the lower limit position of Fig. 6 with about 60 degrees rotation of lthe cams. When the plate member 22 has reached the position of Fig. 6, the plate member 22, the toothed wheel l2, the master sprocket 'II and the film are stationary; and the cam face 55 engages the bali 6|, withdrawing -the claw from the then stationary wheel 12 before the plate member 22 starts upward with the claw 62 still withdrawn from the toothed 6 wheel. The .lm is'xalwaysfgstationary when the jaw 62 moves into or out of mesh with the teeth ll. The teeth of the master sprocket 'II are always meshed with the perforations` of the lm thus avoiding damage to the film perforations.

Iclaimasmyinvention: -v l l. A film feed mechanism comprising a reciprocatoryvmember; a rotary drive shaft having cams thereon; means operated by the cams to reciprocate the member; a sprocket shaft carrying a toothed wheel and a sprocket; a lever pivoted on saidmember andv substantially longitudinally reciprocated bythe member and having a claw; an in-and-out cam on said drive shaft against which the said lever is urged, to move the claw to and from the toothed wheel as the lever'reciprocates to move the wheel step-bystep. x

2. A film feed mechanism comprising a reciprocatorymember having fast thereon opposing abutments transverseto its path; a rotary drive shaft; cams fast on said shaft, at all times engageable with said abutments the cams being contoured to reciprocate the member and hold itstationary for a time at each limit of movement; a sprocket shaft below and transverse to said drive shaft carrying a sprocket and a toothed wheel; a lever intermediately pivotally mounted on said member and having at one end a claw engageable in the spaces between the teeth of the wheel; and an in-and-out cam on said drive shaft having a cam face against which the other end of said lever is'urgedgsaid cam face being contoured to move the claw to and from said spaces when said member is stationary and to hold the claw in said spaces when said member moves in vone direction and away from said spaces when the member moves in the opposite direction.

3. A lm lfeed mechanism comprising a reciprocatory member having fast thereon opposing abutments transverse to its path; a rotary drive shaft;vfveed and take-up cams fast on said shaft and havingl peripheral cam faces, the faces of the cams respectively being at all times engageable with said abutments respectively, the peripheral faceof the cams beingcontoured to reciprocate the member and holdv it stationary for a time at each limit of movement; a sprocket shaft below andtransverse to said drive shaft and carrying a toothed wheel and -av;sprocket; a lever intermediately pivotally mounted o n said member-and having a claw engageable in the spaces between the teethof the toothed wheel; and an in-and-out` cam on said/ drive shaft having a cam face against `which the upper end of said lever is urged; said cam face being'contoured to move the clawl to and from said spaces when said member is stationary and to hold the claw in said spaces when'fsaid member moves in one direction and away from said spaces when the member moves in the other direction.

Y 4. In combination a mounting plate; a reciprocatory plate member vertically slidably mounted on said mounting plate; a` main shaft rotatably mounted on the mounting plate; means carried respectively by the shaft and reciprocatory plate for reciprocating the latter as the shaft rotates; a cam collar having a hub fast on the main shaft and having a flange provided with an in-and-out cam face; a sprocket shaft carrying a toothed wheel and aA film feed sprocket; an oscillatory shaft mounted across said plate member transverse to the path of the latter; a follower lever fast on the oscillatory shaft and having an en- @reserve t gagement end engageable vwith 'the :in-and-'out cam face, said lever carrying .a lower claw adapted to move `in .and vout to engage between teeth of the toothed wheel.

5. A film feed mechanism comprising ka housing; a reciprocatory member therein; a rotary drive shaft mounted in Walls of the housing; cams on said drive shaft; means operated by the cams to reciprocate the member; a sprocket shaft mounted across the housing below said drive shaft and carrying a toothed wheel and an exterior sprocket; a lever on said member having a claw; and an in-'and-out cam on said drive shaft against which the said lever is urged to move the claw to and from the toothed wheel to move it step-by-step.

6, A nlm feed mechanism comprising a housing; a reciprocatory member therein; a rotary drive shaft mounted on the walls of the housing; means operated by the shaft to reciprocate the member, a sprocket shaft 'mounted across the housing below said drive shaft and carrying a toothed wheel and 'an exterior' sprocket; a lever on said reciprocatory member .having a claw; and an in-and-out cam on said drive shaft against which the said lever is urged, to move the claw to and 'from the toothed wheel to move it step-by-step.

7. A nlm feed mechanism comprising a nous ing; a vertically reciprocatory plate member therein having lower bearing ears having transn verse bores; a rotary drive shaft mounted in walls of the housing; means operated by the shaft to reciprocate the member; a sprocket shaft mounted across the housing below said drive' shaft and carrying a toothed wheel and an exterior sprocket; an in-and-out cam on said drive shaft having a transverse cam face; an oscillatory shaft in said transverse bores of the ears; a lever of metal plate fast' on the oscillatory shaft between said ears; said lever having a rounded face in engagement with the in-and-out cam face; the upper part of the lever being rearwardly ex tended and having an upwardly extended end; a ball cup on said end and adjacent to the' periphery of said cam face; a bearing ball in said cup engaging the in-and-out cam; a spring urging the upper end of the lever toward the inand-out cam; the other end portion of the lever extending downwardly and having a rearwardly turned claw engageable between the teeth of the toothed wheel.

8. A lm feed mchanism comprising a housing; a vertically reciprocatory member therein; a rotary drive shaft mounted in walls of the nous--l ing; means operated by the shaft to reciprocate the member; a sprocket shaft mounted across the housing below said drive shaft and carrying an exterior sprocket; a lever intermediately piv oted on said member having a lower toothed wheel made of hard fiber secured fast on the sprocket shaft in the plane of movement of the claw and provided with teeth each comprising a cylindrical outer portion axially parallel to the sprocket shaft and a narrower inner neck; an in-and-out cam on said drive shaft having a transverse cam face 'against which said lever is urged to move the claw to and .from the spaces between the teeth; said claw being thick and having a rounded end and curved upper and lower 'faces substantiallyv coaxial with the pivotal axis of the lever; said cam face, the lengths of the lever arms, the faces of the claw and the movements of said member being so related that the claw is `in retracted position as it moves upwardly and moves inwardly, out of contact with the tooth next above, while thereciprocatory member is stationary, to slide evenly on ther upper face of the cylindrical portion of a tooth next below just above the level of the axis of the sprocket shaft just before the claw moves downward, and engages the cylindrical portions of both adjacent teeth just before the claw is retracted while the reciprocatory member is 'stationary in its lowest position, thus to prevent overfeed of the toothed wheel; the shape of the curved faces of the claw avoiding movement of the toothed Wheel during insertion and retraction of the claw.

9. A film feed mechanism comprising a reciprocatory member; a rotary drive shaft mounted in the walls of the housing; means operated by the shaft to reciprocate the member; a sprocket shaft mounted below said drive shaft transversely thereto and carrying a toothed Wheel and sprocket each tooth of the wheel comprising 'a rounded outer end and a narrow inner end; a lever on said reciprocatory member having a thick claw adapted to snugly engage between said outer ends of adjacent teeth; and an in-'and-out cam on said drive shaft against which the said lever is urged, to move the claw to and from the toothed wheel to move it step-by-step.

TILGHMAN G. FREDERICK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 623,410 Miller et al Apr. 18, 1899 646,287 Hundhausen Mar. 27, 1900 957,246 Paulson May 10, 1910 1,262,798 Huebotter Apr.v 16, 1918 1,283,661 Carlson Nov. 5, 1918 1,322,304 Hartley Nov. 18, 1919 1,326,410 McMillan Dec. 30, 1919 1,363,290 Thevenin Dec. 28, 1920 1,396,666 Rix Nov. 8, 1921 1,833,339 Seufert Nov. 24, 1931 1,893,189 Watts et al Jan. 3, 1933 1,968,250 Frederick et al July 31, 1934 2,008,973 Tuttle July 23, 1935 2,228,773 Merta Jan. 14, 1941 FOREIGN PATENTS Number Country Date 441 Great Britain of 1898 488,497 Great Britain July 7, 1938 679,932 Germany Aug. 17, 1939 

